In production or processing machines, for example printing presses, the webs of material to be produced or to be processed are often longitudinally cut on their way through the machine, and the partial webs being created are thereafter conducted to further processing stages. For this purpose the partial webs are conducted over guide rollers of various types, some of which extend over the entire width of the machine. In order to prevent sagging, such long guide rollers must then be designed to be appropriately heavy and have a correspondingly great inertia. In contrast thereto, a partial web touches or loops around only a portion of the length and has a distinctly reduced cross section in comparison with the entire web. These two effects cause increased fluctuations of the partial web, in particular during start-up operations or, for example, during regulation- or production-based speed changes, and therefore in losses in quality of the product, or even a web break.
WO 01/70608 A1 discloses a turning bar arrangement, wherein two turning bars of a substantially partial web width, are arranged, each on a support, transversely displaceable in respect to the direction of the incoming partial web. A registration roller is arranged respectively laterally outside the lateral frame, whose longitudinal axis extends substantially parallel with the lateral frame, and which is also transversely displaceable along a rail in respect to the direction of the incoming partial web.
A guide element, embodied as a registration roller, is disclosed in DE 36 02 894 C2, which is embodied so that its position can be changed and thereby changes the web path.
A frame in GB 1 546 798, having a plurality of turning bars and a plurality of registration rollers, can be moved as a whole laterally in respect to the incoming web. This entire frame can be replaced for taking various web divisions into account.
In GB 594 035 a deflection roller for already folded strands is disclosed downstream of the formers, which has several individually rotatable roller sections over the width of the strand.